Making an AttackEach character has an Attack Rating, generally 10+(Str/Dis) or 10+(Agi/Int), depending on whether the attack is melee or ranged, respectively. Some weapons grant a bonus to Attack Rating.

A character first declares an attack (and the usual modifiers may apply to the attack rating). After determining if the attack was a success or not (which we'll come to later), the attacker can roll damage. If the damage exceeds the defender's Fortitude, the defender takes damage to his hit points. If the damage is lesser, the defender instead takes vitality damage.

Defending Against an AttackIn order to avoid being hit by an attack entirely, the defender is entitled to make a defense roll (Agi). If the roll is greater than or equal to the Attack Rating, the attacker misses.

Defenders that are unable to defend themselves (e.g. by being incapacitated, immobilized, or the like) do not receive a defense roll against normal attacks.

FortitudeA character's Fortitude allows them to take vitality damage instead of hit point damage. Generally, a character's Fortitude is the highest of their Strength and Discipline modifiers. Armor adds bonuses to Fortitude.

Hit PointsA character's hit points represent the actual punishment the character can take. A character's hit points start at the sum of their Constitution and Discipline scores and increase little throughout their career.

VitalityA character has vitality equal to their Constitution and Presence scores, with an extra +4 bonus for being a heroic character. Vitality is often used to prevent hit point damage from being taken.

By default, a character with less than full hit points can lose 1 vitality every minute to regain 1 hit point.If I implement short rests, then you'll be able to switch over probably Discipline score per rest.

Notes

Zen Archery is in by default, further archetyping Intuition as the quintessential Ranger skill.

The same people who rock melee also rock taking damage. Not intentional, but makes sense. Don't get up close if you can't take a hit. Relatedly, Fortitude numbers are probably a bit low (really, Str/Dis isn't less than Str/Dis in any case. Armor should fix, though).

Constitution is still the HP stat, which is okay. Other things get in a bit (most notably "Intelligence"there's purposely no direct equivalent and "Charisma"). Brings a little bit of MAD to everyone.

No room for attacker simply being a klutz aside from low stats. This may also not be a problem.

Two rolls per attack means both characters get to be involved in the swing.

Permanent or even long-lasting damage is simply not there. Recuperating after a battle is done in minutes, not days. Heroic, yes. Realistic, no. Variant rules can alleviate this later.